ref: a48b462e4464c762fac0c8fa0af18d05db2a725f dir: /sys/src/ape/lib/ap/plan9/setgid.c/
#include <sys/types.h> #include <unistd.h> #include <errno.h> /* * BUG: never works */ int setgid(gid_t) { errno = EPERM; return -1; }